I've seen a few. I'm generally unimpressed. There is a bunch of hype that surrounds them (almost as bad as, say, the hype around Kiger Mustangs). Most of the hype is bunk promoted by the McCurdy boosters (the way most of the hype around the Kigers is bunk, promoted by their boosters).
Evaluate a McCurdy (or a Kiger) the way you'd evaluate any other horse: conformation, way of going, and temperment. Then make your call.